1 files changed, 16 insertions, 0 deletions
diff --git a/src/test/ui/borrowck/suggest-as-ref-on-mut-closure.rs b/src/test/ui/borrowck/suggest-as-ref-on-mut-closure.rs
new file mode 100644
index 000000000..1dcf04618
--- /dev/null
+++ b/src/test/ui/borrowck/suggest-as-ref-on-mut-closure.rs
@@ -0,0 +1,16 @@
+// This is not exactly right, yet.
+
+// Ideally we should be suggesting `as_mut` for the first case,
+// and suggesting to change `as_ref` to `as_mut` in the second.
+
+fn x(cb: &mut Option<&mut dyn FnMut()>) {
+    cb.map(|cb| cb());
+    //~^ ERROR cannot move out of `*cb` which is behind a mutable reference
+}
+
+fn x2(cb: &mut Option<&mut dyn FnMut()>) {
+    cb.as_ref().map(|cb| cb());
+    //~^ ERROR cannot borrow `*cb` as mutable, as it is behind a `&` reference
+}
+
+fn main() {}